The objective of this investigation is to examine the effects of otitis media with effusion (OME) on children's hearing, speech, and language competencies and to delineate any communication sequelae of this ubiquitous childhood illness. The immediate and long-term effects of middle ear effusion on communication abilities remain controversial for a number of reasons including retrospective study designs, small sample sizes, poorly documented hearing histories and otologic findings, inadequate outcome measures, and failure to assess children at more than one age. In this study, the effects of middle ear effusion on the auditory, cognitive, speech and language capabilities of infants and young children will be examined using age-appropriate measures selected to probe both global and specific communication competencies. A large cohort of children will be followed prospectively beginning at term. Our previous experience with a similar population indicates that a significant number of these children will develop recurrent OME, while others will remain otitis free. This cohort will receive periodic audiolobic, otoscopic, and acoustic immittance assessments during the first three years of life, thereby prospectively documenting their peripheral hearing status and middle ear function. Other auditory measures will be administered at specified intervals in order to examine children's higher-order processing capabilities. All children will receive assessments of their receptive and expressive language abilities, cognitive capacities, and behavior. Perceptual and acoustical phonologic analyses of children's spoken language (including infant vocalizations) will be performed regularly. Our aim is to examine the immediate and longer-term consequences of OME on emerging and established communication competencies using specific and global measures of performance.